列'*'在选择列表中无效，因为它不包含在聚合函数或GROUP BY子句中

Question

我有一个如下查询

select a.EmployeeName, 

STUFF(( SELECT ',' + camTable.DepartmentName AS [text()]
                        FROM EmpoyeeDepartment subTable
                left join DepartmentTable camTable on subTable.DepartmentID = camTable.DepartmentID 
                        WHERE
                        subTable.EmployeeID = a.EmployeeID
                        FOR XML PATH('')
                        ), 1, 1, '' )
            AS Departments
from 
EmployeeTable a
where a.EmployeeID = 144025
group by EmployeeName, Departments

但是当我执行上面的sql时，出现了一个错误：

Column 'EmployeeTable.EmployeeID' is invalid in the select list because it is not contained in either an aggregate function or the GROUP BY clause.

预期结果：

上面的sql有什么问题？

Answer 1

我认为这是因为group by子句中缺少EmployeeID列。 子查询中指定的列也应包含在group by子句中。

请试试：

select a.EmployeeName, 

STUFF(( SELECT ',' + camTable.DepartmentName AS [text()]
                        FROM EmpoyeeDepartment subTable
                left join DepartmentTable camTable on subTable.DepartmentID = camTable.DepartmentID 
                        WHERE
                        subTable.EmployeeID = a.EmployeeID
                        FOR XML PATH('')
                        ), 1, 1, '' )
            AS Departments
from 
EmployeeTable a
where a.EmployeeID = 144025
group by EmployeeID, EmployeeName, Departments 

Answer 2

使用子查询

SELECT Z.EmployeeName,Z.Departments FROM (
   select a.EmployeeName, 

   STUFF(( SELECT ',' + camTable.DepartmentName AS [text()]
                        FROM EmpoyeeDepartment subTable
                left join DepartmentTable camTable on subTable.DepartmentID = camTable.DepartmentID 
                        WHERE
                        subTable.EmployeeID = a.EmployeeID
                        FOR XML PATH('')
                        ), 1, 1, '' )
            AS Departments
  from 
  EmployeeTable a
  where a.EmployeeID = 144025
) Z
group by Z.EmployeeName, Z.Departments